JP2775899B2 - Control device for turbocharger with rotating electric machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for a turbocharger with a rotating electric machine in which a motor-generator is mounted on a rotating shaft of a turbocharger.

(Prior art) Since the exhaust gas emitted from the internal combustion engine is high temperature and high pressure,
Various methods and devices for recovering this energy as driving force or electric power have been proposed in the past.

As this type of exhaust energy recovery device, a rotating electric machine serving as a motor-generator is mounted on a turbine shaft driven by exhaust energy, and a supercharging operation by the rotating electric machine is performed based on an engine load state and an accelerator pedal depressed state. Japanese Patent Application Laid-Open No. 63-272909 discloses a proposal of a control device of a turbocharger with a rotating electric machine for controlling the supply of fuel and fuel.

FIG. 4 is a block diagram showing a main part of the proposal disclosed in the above-mentioned publication, and shows an exhaust pipe 1b and an intake pipe 1a of the engine 1.
Is connected to a turbocharger 2 having a turbine 2b and a compressor 2a, and a rotating electric machine 3 serving as an electric-generator is attached to the turbine rotating shaft 2c.

Reference numeral 5 denotes a battery, and 6 denotes a controller comprising a microcomputer and having a high-power device in an input / output circuit. The controller receives a signal from an accelerator sensor 1c, a load sensor 1d of the engine, and the like. 5
In addition to increasing the boost pressure by electrically driving the rotating electric machine with electric power from the engine, the fuel supply is increased, and an engine output corresponding to the maximum depression amount of the accelerator pedal is obtained even when the engine is under heavy load. . 1e is an engine rotation sensor, and 1h is a boost pressure sensor.

If the accelerator pedal is at the maximum depression amount, as shown in the processing flow diagram of FIG.
pm level, turbine speed (rotating electric machine speed)
However, if it is below this level, the power supply from the battery is maximized (step c).

If the turbine speed is equal to or higher than the Lrpm level in step b, the process proceeds to step d.If the turbine speed thereafter increases, the process proceeds from step e to step f to reduce the supply current by a predetermined amount, When the turbine rotational speed is decreasing, the process proceeds from step e to step g to control the turbine rotational speed without changing the supply current.

(Problems to be Solved by the Invention) Therefore, in the above proposal, when the turbine speed falls below a predetermined set value, the power supplied from the battery is maximized to increase the turbine speed regardless of the degree of the decrease. For this reason, as shown in FIG. 6, there is a disadvantage that the motor speed largely rises and falls near the Lrpm level and does not converge at a constant rotation speed, and that the power consumption is increased due to the supply of large power. Has occurred.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a control device for a turbocharger with a rotating electric machine that attempts to reduce fluctuations in the rotational speed difference in the vicinity of the controllable rotational speed of the electric rotating machine. To provide.

(Means for Solving the Problems) According to the present invention, a turbocharger with a rotating electric machine that controls a supply current to a rotating electric machine serving as a motor-generator provided in a turbocharger and controls a supercharging amount to an engine. In the control device for the charger, a predetermined rotation speed level at which the rotating electric machine can be electrically controlled is provided, and a current increase to increase a supply current to the rotating electric machine based on a rotation speed decrease amount of the rotating electric machine near the predetermined rotation speed level. A control device for a turbocharger with a rotating electric machine provided with a means is provided.

(Operation) Since a predetermined rotational speed level at which electric control of the rotating electric machine provided in the turbocharger can be controlled is set, and the current supplied to the rotating electric machine is increased based on the amount of decrease in the rotating speed of the rotating electric machine near the predetermined rotational speed. Unlike when the maximum current is supplied, the rotation speed gradually increases and reaches a predetermined rotation speed, thereby suppressing a rapid increase in the rotation speed and further reducing the power consumption.

Example Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration block diagram showing one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an engine which drives a vehicle (not shown) by combustion energy of air taken in through an intake pipe 1a and fuel supplied from a fuel tank 1g through an injection pump 1f. The exhaust gas after combustion is discharged through the exhaust pipe 1b. 1c is an accelerator sensor that serves as a means for detecting the amount of depression of the accelerator pedal, 1d is a load sensor that serves as a load detecting means for the engine by detecting the rack position of the injection pump 1f, and 1e is a rotation sensor that detects the number of revolutions of the engine. The detected signals are transmitted to the controller 6 described later.

Reference numeral 2 denotes a turbocharger connected to the exhaust pipe 1b and the intake pipe 1a, and a turbine 2b driven by exhaust gas.
And a compressor 2a for sending compressed air to the intake pipe 1a, and a rotary shaft for connecting these turbines and the compressor.
2c is a rotating electric machine 3 operating as a motor or a generator.
Is installed.

The rotating electric machine 3 has a rotor 3a and a stator 3b. When the rotor 3a is rotationally driven by exhaust energy, the
The AC power is generated in 3b and transmitted to the battery 5 via the power converter 4.

When the rotor 3a is driven by the electric power from the battery 5 via the power converter 4, the intake air is compressed by the operation of the compressor 2a, and the engine 1 is supercharged through the intake pipe 1a. I have. In addition, 1h is a boost pressure sensor which detects the supercharging pressure due to the operation of the compressor 2a and transmits it to the controller 6.

The power converter 4 receives AC power from the stator 3b when the generator is operating, converts the AC power into, for example, charging power for the battery 5, or converts DC power from the battery 5 for driving the rotating electric machine 3 into an electric motor by a predetermined amount. It converts to AC power.
Therefore, in addition to a rectifier circuit and a smoothing circuit for converting alternating current to direct current, a converter for high power such as an inverter for converting direct current to alternating current and a booster circuit are provided. Is controlled by In addition, 3c is an AC measuring device that measures the voltage value, the current value, the phase between them, etc. of the AC power that is converted by the power converter 4 and supplied to the stator 3b, and 4a is the DC power that is converted by the power converter 4. It is a DC meter for measuring voltage and current, and transmits measured values to the controller 6 respectively.

The controller 6 is composed of a microcomputer, a central processing unit that performs calculations such as supplied fuel, required power, and boost pressure based on the operating state of the engine 1 and signals from various sensors, a memory of the results of these calculations, the engine, and the rotation speed. It has various memory devices for storing the control program of the electric machine, and input / output devices for receiving various inputs and issuing control instructions to related parts. The rotation speed of the rotating electric machine based on the frequency of the back electromotive force induced in the stator 3b when the rotating electric machine 3 rotates is configured to be input to the controller 6.

FIG. 2 is a processing flowchart showing an example of the operation of the present embodiment,
FIG. 3 is a curve diagram showing an example of the relationship between the current supplied to the rotating electric machine and the engine speed, and the operation will be described with reference to these drawings.

First, in step 1, it is determined from the signal of the accelerator sensor 1c whether or not the amount of depression of the accelerator pedal is the maximum. If it is the maximum, the process proceeds to step 2;

In step 6, the target boost pressure Pt is compared with the actual boost pressure PB. If the difference is larger than the acceleration determination boost differential pressure KB (acceleration state), in step 11, the supply current is calculated according to the boost differential pressure. And proceed to the flow.
If the boost differential pressure is smaller than the above KB, the process proceeds to step 12, and the mode is determined.

When the process proceeds from step 1 to step 2, it is determined whether or not the turbine speed has exceeded Lrpm (a level provided in the vicinity of the controllable rotational speed of the electric rotating machine) in the past. If so, the routine proceeds to step 7, where the current turbine speed is compared with Lrpm.

And, if it is lower than Lrpm, based on the engine speed,
After calculating the supply current, the process proceeds to. If the current turbine speed is equal to or higher than Lrpm, the flow follows in step 8 when the turbine speed does not exceed Lrpm in the past.

Here, in Step 2, the turbine rotational speed was
If the above has not been reached, the process proceeds to step 3, which is determined from the current turbine speed. If the speed is equal to or less than Lrpm, the supply current is set to the maximum value in step 4, and the current is applied in step 5 to reduce the speed. Increase.

If the speed is equal to or higher than Lrpm in step 3, step 8
Then, the turbine rotation speed is compared with the motor operation controllable upper limit rotation speed Hrpm of the rotary electric machine.

If the rotational speed is equal to or less than Hrpm in step 8, the process proceeds to step 9 to check whether the turbine speed is increasing or decreasing. If the rotational speed is increasing, the process proceeds to step 10 in which the supply current is reduced by a predetermined value. move on. Further, in the case of a decrease in step 9, a process of continuously operating without changing the supply current is performed.

Hereinafter, the present invention has been described with reference to the above embodiments. However, various modifications are possible within the scope of the present invention, and these modifications are not excluded from the scope of the present invention.

(Effects of the Invention) According to the present invention, when the turbine speed is near a predetermined set value, according to the rotation difference near the set value, an appropriate current corresponding to the difference is controlled to be supplied to the rotating electric machine. As shown in FIG. 6, there is an effect that the wide fluctuation range is reduced and reduced, and the supply current is appropriately controlled.
There is an advantage that power consumption is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG.
FIG. 3 is a process flow chart showing an example of the operation of the present embodiment, FIG. 3 is a curve chart showing an example of an engine speed and a supply current to a rotating electric machine in the present embodiment, and FIG. FIG. 5 is a block diagram of a conventional example, FIG. 5 is a processing flow diagram of the conventional example, and FIG. 6 is a chart showing turbine rotation fluctuation in the conventional example. 1 ... Engine, 1c ... Accelerator sensor, 1d ... Load sensor, 2 ... Turbocharger, 3 ... Rotating electric machine, 4 ...
... power converter, 5 ... battery, 6 ... controller.

Claims (1)

(57) [Claims] A control device for a turbocharger with a rotating electric machine for controlling a supply current to a rotating electric machine serving as a motor-generator provided in the turbocharger and controlling a supercharged amount to an engine. A rotating means provided with a predetermined rotational speed level which is electrically controllable, and a current increasing means for increasing a supply current to the rotating electric machine based on an amount of rotation decrease of the rotating electric machine near the predetermined rotating speed level; Control device for an electric turbocharger.